Slow Warm Engine Cranking/Start

Engine troubles? Try here.
User avatar
ElectraPinz
Posts: 36
Joined: Wed Feb 16, 2011 6:37 pm
Location: Durango, CO

Re: Slow Warm Engine Cranking/Start

Post by ElectraPinz »

I jumped over to a different thread that was dealing with the ignition stuff:

viewtopic.php?f=12&t=6538

Some good info there.

Ben
User avatar
ElectraPinz
Posts: 36
Joined: Wed Feb 16, 2011 6:37 pm
Location: Durango, CO

Re: Slow Warm Engine Cranking/Start - Problem Solved

Post by ElectraPinz »

Finally got the Pinz out from under the snow and installed one of EI's gear reduction starters.

That is an amazing piece of hardware - like night and day.

Engine starts right up every time.

Ready to rock 'n roll!! :D
User avatar
ElectraPinz
Posts: 36
Joined: Wed Feb 16, 2011 6:37 pm
Location: Durango, CO

Re: Slow Warm Engine Cranking/Start

Post by ElectraPinz »

With a new gear reduction starter, fuel pump (VW type), new fuel filter, noise suppressor removed (civilian ignition installed la year agi), generally upgraded ignition wiring, the Pinz has been starting and running great for the past month. Only gripe has been a bit of hesitation on pulling a hill at full throttle (I should have taken the hint).

Then it died, fortunately not up on the mountain. No gas. (great to be able to get robust engine cranking to see what’s happening - thanks to gear-reduction starter!) After hauling the Pinz back to the barn, I was embarrassed to discover that the fuel filter was clogged (? Some initial resistance when I blew in the “outy” end). Put it back together and it started right up and ran fine.

Since I drive a lot in the high mountains alone and out of cell phone range, I’m thinking redundancy and better controls. Here are my thoughts; what are yours?

A. Coil Voltage (+ terminal): A voltmeter would tell me if and when the voltage is dropping below 14, which would be a warning. I had to deal with this issue a year ago.

B. Fuel Pressure and flow: The repair manual says “minimum feed at 4000 rpm amounts to 24 liters of fuel, the feed pressure to 0.3 bar.” If my calcs are correct, that’s 6.34 gph and 4.35 psi (minimum feed/max pressure at maximum rpm). Jim L has posted on this Forum, “The Pinz runs 1.5-2.5psi on average.” Given that the fuel pump output varies with rpm (I presume), these seem like pretty minimal numbers, with slight room for degradation. A 0-5 psi fuel pressure gauge ($30 plus connecting hardware) would give me some indication of performance.

C. I’m thinking of adding redundancy by plumbing an electric fuel pump (with integral filter) parallel to the mechanical pump/filter, isolated by check valves and with appropriate “crash and burn” protection. The redundant fuel pump could be switched on from the dash. I estimate about $300 for the hardware.

D. Elec vs mechanical fuel pump: I’m almost tempted to install two electric fuel pumps. I’ve seen some “Savy” members posts, “If it ain’t broke don’t fix it.” But it is difficult to understand how or why the carbs would work better or more efficiently/reliably with a variable flow variable pressure supply than with a constant flow constant pressure (regulated) supply. Somewhere on this forum, I read that the float valves can handle pressures up to 4.5-5 psi. So, at the high end, everything is probably equal. But at low- to mid-rpms under full load, it seems that a marginal mechanical fuel pump could be starved more easily than an electric pump. Not being that much of an automotive engineer, I just dunno, but would like to. The engines I have worked on before have had much more robust fuel pumps.



.
Post Reply